1. Field of the Invention
The invention pertains generally to ignition devices and systems. More particularly, the invention relates to thermally activated ignition devices and systems. In greater particularity, but without limitation thereto, the invention pertains to an ordnance device that aligns and initiates a triggering primer in response to temperature change.
2. Description of the Prior Art
Energetic materials, such as explosives and propellants, pose the extreme hazard of being inadvertently detonated due to unplanned or accidental stimuli. This hazard is multiplied significantly when these materials are stored in close proximity, as a single unintentional detonation can lead to repetitive, sympathetic detonations. Such unintentional detonations have the potential of destroying not only life and limb, but also the containment structures in which they occur. This potential for destruction is particularly high when these materials are carried aboard oceangoing vessels.
Much work has been done to lessen the possibility of the inadvertent detonation of energetic materials. Sequential explosive initiators or detonators are standard in the art, as are well-thought-through schemes for storing and housing explosive substances. Yet, few advances have been made in safeguarding explosives, propellants or other energetic materials from the effects of heat due to fire.
Members of the art generally concur that two distinct fire environments must be dealt with in order to nullify the potentially disastrous effects of mixing energetic materials with fire. One such environment subjects these materials to a gradual heating over a relatively long period of time, for example, an increase in environmental temperature of six degrees Fahrenheit per hour. This environment has become known as a slow cookoff environment. Another such environment exposes these explosive materials to a rapid heating to elevated temperatures, such as an increase in environmental temperature of 1000 degrees Fahrenheit in 30 seconds with average sustained temperatures of about 1600 degrees Fahrenheit thereafter. This rapid, high temperature condition has become known as a fast cookoff environment. In either of these cases, it is desirable that detonation of the affected materials be avoided, that is, that the materials be rendered inert before detonation temperatures are reached.